The purpose of this study is to examine whether transformational and transactional leadership influence organizational citizenship behavior (OCB), and to investigate whether subordinates' trust in their leader serves as a mediating variable between these constructs. To achieve this purpose, an empirical study using a survey method was conducted with 679 employees working at 50 deluxe (first- and second-class) hotels in Korea, which can better represent organizational citizenship behavior. The analysis results showed that transformational leadership had a positive effect on organizational citizenship behavior, whereas transactional leadership did not have a positive effect on organizational citizenship behavior. Furthermore, transformational leadership was found to have a closer relationship with organizational citizenship behavior and trust than transactional leadership. Finally, when testing whether trust in the leader exhibits a mediating effect in the relationship between leadership and organizational citizenship behavior, transformational leadership was found to exert even greater influence through trust, whereas no mediating role was found for transactional leadership.